Shuffling is known as an efficient coding means for recording existing television signals.
In this technique, a block arrangement composed of input digital video signals is divided into plural regions, a specific number of blocks are obtained from specific positions of each region to form video segments, and while sequentially shifting the specific positions in each region, video segments are formed progressively. Accordingly, the data correlation within the video segment is weakened, and fluctuations of the data length of digital video signals within each video segment can be prevented at the time of the coding process.
When applying shuffling to high definition television (HDTV) signals, sharing of the complex hardware of the shuffling circuit by digital television signals of different standards is desirable. At present, there are three standards of HDTV as specified by the number of scanning lines and field frequency, that is, 1125 lines/60 Hz (hereinafter called 1125 system), 1050 lines/60 Hz (1050 system), and 1250/50 Hz (1250 system). Between the 1050 system and the 1250 system, the number of horizontal active pixels per line is the same, and the circuit can be shared by varying the offset value in the vertical direction. In the 1125 system, however, since the number of horizontal and vertical active pixels are both different from the other standards, and there is no matching at all, sharing of the circuit is extremely difficult.